Automatic drill cuttings sampler



March 22, 1966 J. M. HORETH AUTOMATIC DRILL CUTTINGS SAMPLER Filed Jan.25, 1962 2 G F S %T l N HU W R W 2 W I OT L m 0A F S R O T A R B 7 V 7|23 ll i l lI'i |I 8 I w 2 l 2 v W 2 O 3 2 2 w 2 2 JOHN M. HORETHINVENTOR.

M2762 AGENT United States Patent 0 3,241,371 AUTOMATIC DRILL CUTTllNGSSAMPLER John M. Horeth, Tulsa, Okla, assignor, by mesne assignments, toEsso Production Research Company, Houston, Tex., a corporation ofDelaware Filed Jan. 25, 1962, Ser. No. 168,699 8 Claims. (Cl. 73-422)This invention is directed to apparatus for obtaining samples ofentrained particulate solids contained in a flowing stream of fluid, andmore specifically, for obtaining samples of cuttings from drillingoperations. A device is provided for automatically collectingrepresentative samples of fine cuttings directly from. a circulatingstream of drilling fluid.

In the process of drilling boreholes into the earth, such as oil and gaswells and the like, a drilling fluid is continuously circulated from thesurface of the earth to the bottom of the hole and back in order to cooland lubricate the drill bit, carry away the cuttings, and form animpervious coating on the wall of the borehole. The drilling fluid ormud being returned from the drill hole is discharged on to a shaleshaker which typically comprises a screen and means for agitating thescreen. The shale shaker is usually mounted above a mud tank where thelarger cuttings are retained while the mud flows through into the mudtank for recirculation. It is com mon practice to sample the cuttingsfrom the shale shaker to maintain a record of the formation beingpenetrated by the drill bit. Such samples have been collected more orless sporadically by manually catching a sample of the cuttings as theyare discharged from the screen of the shale shaker. Such cuttings werethen manually washed to remove adhering mud and then sacked for eventualinvestigation.

It is diflicult by such methods to satisfactorily correlate a givensample with an exact depth within the borehole. Not only is the manualapproach inherently unreliable; there is also inadequate control of theparticle size of the cuttings recovered from the shale shaker. Bysampling from the circulating mud stream directly, fine cuttings whichare usually lost over the shale shaker screen can be collected.Frequently, the fine cuttings are important in the evaluation of theformation interval being penetrated by the drill bit. Thus, it isobviously desirable to obtain representative samples of a controlledparticle size. The apparatus provided by the invention achieves thisresult.

Proper evaluation of formations being penetrated by a drill bit dependsalmost entirely upon the availability of representative drill cuttingsamples. In fact, careful examination of properly collected cuttings canyield data surpassing much of that obtainable from the most expensivewell logging instruments in use today. In many instances, however, thecollected samples are inadequate because of careless collectingtechniques. Particularly, much of the fine sand cuttings from friablesandstones pass through the shale shaker screen. Detection of these finecuttings is frequently of prime importance since they may represent keystratigraphic markers or hydrocarbon reservoirs.

In a rotary drilling rig, the drilling fluid return line which runs fromthe well head to the shale shaker is sub stantially horizontal, with aslight slope downward from the well head to the shale shaker. Theapparatus of the invention is adapted for attachment to this section ofthe drilling fluid return line. The device comprises tubular 3,241,371Patented Mar. 22, 1966 means extending through a lower portion of thereturn line and terminating a substantial distance Within the returnline, the terminus of said tubular means having an opening thereinadapted to receive a portion of the contents flowing within the returnline. Hinged valve means are provided in operative association with saidopening, along with means for automatically opening and closing saidvalve means periodically. Second valve means are provided at the otherend of said tubular means, including means for automatically opening andclosing said second valve means while the first valve means is closed.

The apparatus also includes a funnel and washing means for collectingand washing the mud sample as it is dumped from the above mentionedtubular means. The funnel empties onto a sieve screen which isvigorously agitated by conventional vibrating means. The function of thescreen is to hold the cuttings as they accumulate, to grade the sampleas to the desired particle size, and to provide rapid drainage for thewashings. After each preselected interval of drilling depth, for exampleevery ten feet, the accumulated cuttings are removed from the screen asa finished sample, placed in a container and labeled with the drillingdepth.

A detailed description of the invention is provided by reference to theaccompanying drawings.

FIGURE 1 is an elevational view, partly in section, showing a completeembodiment of the apparatus.

FIGURE 2 is a fragmentary elevational view of the preferred embodiment.

The apparatus of FIGURE 1 includes sampler tube 11 adjustably insertedinto flow line 12 and equipped with automatic hinged flapper valves 13and 14. The valves are actuated through linkage means 15 and 16,respectively, driven by solenoids 17. The solenoids operating the twoflapper valves are connected to switches which in turn are operated byan automatic timing device. The switches and timing unit are indicateddiagrammatically by numeral 18. The timer operates the solenoids at asuitable interval, for example, once every half minute. The operation ofthe two valves is staggered. First the valve in the mud stream opens,allowing: the tube to fill with mud. After about 10 seconds it closesagain, then the bottom valve is opened, discharging the contents of thetube.

The sample is directed through funnel 19 onto screen 20 which isagitated by vibrator 21. Funnel 19 is equipped with washing means suchas water inlet 22 and spray nozzles 23. Nozzles 23 may extend around thefull perimeter of funnel 19. The need for vibrating screen 20 arisesfrom the inherent tendency of the drilling fluid to form a gel.Vibration breaks up the gel and thereby facilitates washing of thecuttings, and the passage of discardable fines through the screen, whilethe desired sample is retained.

The mesh size of screen 20 is selected in accordance with the size ofcuttings which it is desired to collect. The preferred size is SO-meshfor typical. use, since cuttings and other particles which pass thisscreen are of little or no value for purposes of geologicalinterpretation. They are simply recirculated in the mud system.

The rate at which cuttings collect on screen 20 depends on the frequencyof sampling and upon the drilling rate. But the sampling rate isarbitrarily selected and held constant. Therefore, the rate of cuttingsaccumulation on screen 20 is made to depend directly upon the drillingrate.

Thus it becomes convenient to control the discharge of cuttings samplesfrom the screen by obtaining a signal from the depth counter of adrilling-time recorder, such as the Geolograph Recorder, manufactured byThe Geolograph Company.

It is common practice to obtain a signal from the Geolograph byinstalling a microswitch to be activated by one of the gears in thedepth counter of that instrument. The microswitch is in turnelectrically connected to a mechanism for discharging the contents ofscreen 20 after each desired interval of drilling depth, for exampleevery ten feet.

Cuttings generally settle to a depth of about 3 to 5 inches along thebottom of drilling fluid return line 12. The depth varies depending onthe flow rate and the average particle size of cuttings contained in thedrilling fluid. Because of the bed of cuttings which tends to form inline 12, the sample tube 11 must extend within line 12 to a level justabove the bed depth in order to permit valve 13 to swing open and shutwithout interference from the bed, and in order that tube 11 may receiverepresentative samples. Accordingly, means for adjusting the distance bywhich tube 11 and flapper valve linkage 15 extend into line 12. areprovided in the form of sleeve 24, having flange 25, secured to adapter26, which in turn is welded to an opening provided in line 12. Flange isalso provided with a bushing 27 to accommodate the movement of linkageassembly 15. Set screws 28 hold the device in place at the desiredlevel. O-ring seals 29 and 30 are provided to prevent leakage aroundtube 11 and linkage 15, respectively. Other means for adjusting theheight of tube 11 may be provided, such as a rack and pinion geararrangement.

The opening in tube 11 covered by flapper valve 13 is shown having a 45inclination facing the drilling fluid flow. Such inclination is deemedpreferable in order to facilitate the entry of a sample into the tube;however, it is not critical since the drilling fluid and cuttings wouldnevertheless enter tube 11 even if the opening were not in clined withrespect to the direction of mud flow. Moreover, tube 11 need not be ofcircular cross-section as shown. It may instead have a rectangularelliptical, polygonal or other cross-section if desired.

Although other valve means may be substituted for the hinged flappervalves 13 and 14, the flapper valves are considered essential if thedevice is to enjoy prolonged, trouble-free operation since other valves,with sliding movements and the like, are readily fouled and eroded byfine cuttings and other solids normally associated with a drillingfluid. A sealing ring of soft rubber or similar material is desirable toprevent leakage of the flapper valve. Springs 31 and 32 are provided tohold the valves in a closed position when not activated by thesolenoids.

Solenoids 17 are not shown in detail since they may be of anyconventional design, as readily appreciated by one skilled in the art.Moreover, the solenoid drive provided for the flapper valves may bereplaced by hydraulic or air driven pistons or the like.

Similarly, the solenoid switches and timer unit are not shown in detailsince they too may be of any conventional design. A suitable unit is theIndustrial Multi- Cam Timer, Model MC-4, obtained from the IndustrialTimer Corp., of Newark, NJ.

Referring now to the preferred embodiment of FIG- URE 2, sleeve 33 isattached to bushing 27 and encloses linkage assembly 15. The sleeve ismade of any tough, flexible material, such as rubber or plastic, and issealed at each end in order to protect linkage 15 from the erosiveaction of entrained solids flowing within line 12. Moreover, sleeve 33replaces O-ring 30 and provides in its place a more positive exclusionof solids from the bore of bushing 27, whereby the operation of valve 13is kept smooth. The sleeve may be shortened, to enclose only the firstjoint of linkage 15, without departing from the scope of the invention.The remainder of the apparatus,

4 not shown in FIGURE 2, is the same as that shown in FIGURE 1.

While various embodiments of the invention have been fully described, itis obvious that further modifications will occur to those skilled in theart. Accordingly, it is intended to include all such modificationswithin the scope of the following claims.

What is claimed is:

1. In a rotary drilling rig, including a conduit system for circulatinga drilling fluid downhole and then back to the surface of the earth, asampling device for obtaining cuttings from drilling fluid in the returnline of said system which comprises: tubular means extending through alower portion of said return line and terminating a substantial distancewithin said return line, the terminus of said tubular means having anopening therein adapted to receive a portion of the contents flowingthrough said return line, hinged valve means connected to said tubularmeans for closing said opening, means for opening and closing said valvemeans, second valve means at the other end of said tubular means, meansfor opening and closing said second valve means, and timing meansconnected to the first and second valve actuating means for coordinatingthe operation of said valves.

2. Apparatus as defined by claim 1, further comprising sieve means incombination with said tubular means and adapted to receive the contentsdischarged from said tubular means.

3. Apparatus as defined by claim 2 further comprising funnel means incombination with said tubular means and adapted to guide the contents ofsaid tubular element, periodically released by said second valve means,onto said sieve means.

4. Apparatus as defined by claim 2, further comprising means incombination with said sieve means for vibrating said sieve means.

5. Apparatus as defined by claim 3, further comprising means incombination with said funnel means for flushing the contents of saidfunnel means onto said sieve means.

6. A sampling device for obtaining representative samples of entrainedparticulate solids contained in a flowing stream of fluid, comprising atubular element; means connected to said tubular element for adaptingone end of said tubular element to be inserted into and attached to aflow line the contents of which are to be sampled; first hinged valvemeans affixed to said one end of said tubular element; means foroperating said valve means comprising a rigid elongated element aflixedto said valve means and extending through an opening provided thereforin said adapting means; a flexible sleeve member enclosing saidelongated element and sealing said opening as a protection against theerosive action of said entrained solids; second valve means aflixed tothe other end of said tubular element; first valve actuating means forperiodically opening and closing said first valve means; second valveactuating means for opening and. closing said second valve means; andtiming means connected to the first and second valve actuating meansfor' coordinating the operation of said first and second valve;actuating means.

7. A device as defined by claim 6, further comprising mounting meanspermitting adjustment of the distance by which said tubular elementextends into said flow line.

8. A device for obtaining representative samples of' entrainedparticulate solids contained in a flowing stream of fluid, comprising atubular element; means connected to said tubular element for adaptingone end of said tubular element to be inserted into and attached to aflow line the contents of which are to be sampled; first hinged valvemeans aflixed to said one end of said tubular element; means foroperating said valve means comprising a rigid elongated element aifixedthereto and extending through an opening provided therefor in saidadapting means, Sefllmg mean$ slidably ngaging said elongated elementand mounted in said opening; second valve means aflixed to the other endof said tubular element; first valve actuating means for opening andclosing said first valve means; second valve actuating means for openingand closing said second valve means; and automatic timing meansconnected to said first and second valve actuating means forcoordinating the operation of said first and second valve actuatingmeans,

References Cited by the Examiner UNITED STATES PATENTS 2,516,097 7/1950Woodham et a1. 73-422 X 2,528,955 11/1950 Hayward 73-153 X 2,665,409 1/1954 Rogers 73-422 X 6 2,750,043 6/1956 Thompson 73-42l X 2,883,8564/1959 Youngman 73-153 X OTHER REFERENCES Periodical: The Oil and GasJournal, article by Paul Reed entitled Methods for Catching Rotary DrillSamples in Oklahoma, June 10, 1937 issue, pp. 42-44 and 48 inEngineering and Operating Section.

RICHARD C. QUEISSER, Primary Examiner.

JERRY W. MYRACLE, JOHN P. BEAUCHAMP,

Assistant Examiners.

8. A DEVICE FOR OBTAINING REPRESENTATIVE SAMPLES OF ENTRAINEDPARTICULATE SOLIDS CONTAINED IN A FLOWING STREAM OF FLUID, COMPRISING ATUBULAR ELEMENT; MEANS CONNECTED TO SAID TUBULAR ELEMENT FOR ADAPTINGONE END OF SAID TUBULAR ELEMENT TO BE INSERTED INTO AND ATTACHED TO AFLOW LINE THE CONTENTS OF WHICH ARE TO BE SAMPLED; FIRST HINGED VALVEMEANS AFFIXED TO SAID ONE END OF SAID TUBULAR ELEMENT; MEANS FOROPERATING SAID VALVE MEANS COMPRISING A RIGID ELONGATED ELEMENT AFFIXEDTHERETO AND EXTENDING THROUGH AN OPENING PROVIDED THEREFOR IN SAIDADAPTING MEANS, SEALING MOUNTED SLIDABLY ENGAGING SAID ELONGATED ELEMENTAND MOUNTED IN SAID OPENING; SECOND VALVE MEANS AFFIXED TO THE OTHER ENDOF SAID TUBULAR ELEMENT; FIRST VALVE ACTUATING MEANS FOR OPENING ANDCLOSING SAID FIRST VALVE MEANS; SECOND VALVE ACTUATING MEANS FOR OPENINGAND CLOSING SAID SECOND VALVE MEANS; AND AUTOMATIC TIMING MEANSCONNECTED TO SAID FIRST AND SECOND VALVE ACTUATING MEANS FORCOORDINATING THE OPERATION OF SAID FIRST AND SECOND VALVE ACTUATINGMEANS.